Advanced billing solutions and rating engines are emerging as key to providing flexible service bundles for telecommunications operators. Rating engines must be able to handle pricing in real-time as networks transition to IP and operators offer more complex bundles of fixed, mobile, and internet services. This creates opportunities for complementary technologies to billing systems that can manage large amounts of subscriber data from multiple sources in real-time through a single global database. Smaller billing vendors may also have opportunities in the growing "greenfield" market as major operators are busy integrating existing infrastructure during mergers.